1. Field of the Invention
The present invention is directed to a method of making food chip products and, more particularly, to a method of making food chip products without cooking oil.
2. Description of the Prior Art
Food chip products such as potato chips and corn chips are popular snack items that typically are obtained by frying potato or corn slices in hot oil so that moisture content of the slices are reduced to a very low level. Fried potato chips prepared using conventional methods usually have an oil or fat content from about 35 percent to about 40 percent by weight.
There have been numerous efforts in the past to reduce the amount of oil in potato chips, but most of these still involve applying some fat or oil to the chip. Nevertheless, the prior art processes have one or more methodological drawbacks that may result in chips having undesirable texture, flavor or color. Also many of the previously published processes are not economically feasible for large scale food chip product production.
For example, Dreher et al., U.S. Pat. No. 4,756,916, is directed to a process for producing low oil potato chips comprising washing potato slices with an aqueous solution, and applying oil to the washed slices to coat the slices with oil. The amount of oil applied to the washed slices is adjusted to achieve an oil content of about 10-25 weight percent in the final product. The oil coated slices are blanched, essentially pre-frying the slices due to the oil coating, and then baked at a temperature of at least about 390.degree. F. to partially dry the slices. The partially dried slices are then further baked at a lower temperature of between about 290.degree. F. (140.degree. C.) to 320.degree. F. (160.degree. C.) to finish drying the slices. The Dreher reference specifically points that oil addition before baking is necessary for the proper development of fried potato chip flavors, and if oil is only added after baking, chip texture is hard and the fried potato chip flavor is not developed. Therefore, while the Dreher reference teaches that oil addition can be completed before or after baking, if oil is added only after baking the chip is less acceptable to consumers.
Kloos, in U.S. Pat. No. 4,906,483, is directed to a process for producing potato products having a no-fat, no-cholesterol and salt-free ingredient characteristics. The Kloos process includes placing a pan containing previously rinsed and sliced potatoes submerged in water into a microwave oven until the submerged potatoes are visibly transparent. After the potatoes are transparent, the water is replaced with cold water to remove visible starch. Once the potatoes are rinsed, they are arranged on a non-stick cooking sheet and are placed in a conventional radiant heat oven for browning and crispening. While disclosing a cooking process for producing potato products without externally-added oil, the reference teaches a process with the combined utilization of a microwave and a conventional radiant heat oven. Similarly, Gaon et al., in U.S. Pat. No. 5,202,139, discloses a process for preparing essentially fat free chips. The process involves cutting and washing raw potatoes, predrying and arranging the sliced potatoes on a conveyor. The slices are arranged on the conveyor in a single layer only and are then exposed to a high intensity microwave field. The slices are then seasoned and exposed to a lower intensity microwave field. While disclosing a process for producing essentially fat free chips, only a single layer of product can be processed. This limitation is due to the nature of microwave cooking and will result in less efficient chip production than a process which can cook multiple layers of food product slices.
Childers, Jr., in U.S. Pat. No. 4,919,965, is directed to a method of processing agricultural produce slices and, more particularly, potato slices by a toasting process. The toasting process occurs by compressive, opposed, contact surfaces which toast sliced produce in a fat and oil-free environment. More specifically, the Childers process includes washing raw agricultural produce and slicing the produce into thin slices. A seasoning is then applied to the slices. The slices are then cooked under heat and pressure imposed between an opposing pair of heating surfaces so as to drive out moisture and toast the slices.
Fazzolare et al., in U.S. Pat. No. 4,873,093, discloses a product and process for preparing a baked snack food from gelatinized starch ingredients. The process of the invention comprises mixing at least one ingredient having starch, such as potatoes, with water to form a composition which is steamed to form a dough-like consistency. The dough-like composition is then machined to form pieces which are baked in a conventional oven. During baking the exterior layer of the dough-like composition cooks rapidly and traps steam in the interior portion of the dough. An alternative embodiment of the process includes applying a spray oil to the pieces before baking to obtain a final product having a flat, cracker-like appearance. In addition, a post-bake oil application is optional and included in a preferred embodiment.
The concern and significant consumer interest in weight control and reduced intake of fats and oils make it important to reduce or eliminate the oil content of food chips.